KR20100121800A - Method for processing hand-over based on pmip for interworking between heterogeneous networks - Google Patents

Abstract

PURPOSE: A handover process method based on PMIP(Proxy Mobile IP) for coupling heterogeneous network is provided to supply handover in heterogeneous network by using PMIP. CONSTITUTION: A wireless terminal is connected to a second wireless network while communicating with a first wireless communication network through a first wireless modem. The wireless terminal assigns a home internet protocol address to a second wireless modem(403). The wireless terminal changes a user traffic path from the first wireless modem to the second wireless modem. The wireless terminal performs a handover. The wireless terminal releases a wireless access connected to the first wireless network.

Description

PMP based handover processing method for interworking heterogeneous networks {METHOD FOR PROCESSING HAND-OVER BASED ON PMIP FOR INTERWORKING BETWEEN HETEROGENEOUS NETWORKS}

The present invention relates to a handover processing method for supporting handover in a wireless terminal, and more particularly, to provide IP mobility between heterogeneous networks (eg, mobile Internet-HSDPA) using PMIP (Proxy Mobile IP). In this case, due to the limitation of the wireless terminal using the Windows OS, the BBM (Break-Before-Make) handover can be solved to solve the disadvantage of enabling the MBB (Make-Before-Break) handover. The present invention relates to a PMIP-based handover processing method for interworking between heterogeneous networks.

Here, BBM (Break-Before-Make) handover refers to a handover of a method of first disconnecting a currently connected wireless connection and then connecting to and communicating with a new wireless network.

In addition, MBB (Make-Before-Break) handover refers to a handover of a method of disconnecting a previous wireless network after completing a connection to a new wireless network.

In the following embodiment according to the present invention, as an example of a heterogeneous network (or referred to as a "heterogeneous wireless network") described as a mobile Internet (WiBro) -HSDPA (High Speed Downlink Packet Access) network as an example, It is not limited to this in advance.

That is, the wireless communication network to which the wireless terminal (handover processing apparatus) having the handover function according to the preferred embodiment of the present invention connects is CDMA (Code Division Multiple Access) operating in a synchronous manner, and WCDMA operating in an asynchronous manner. Wide-CDMA (Wide-CDMA) and / or High Speed Downlink Packet Access (HSDPA) and / or High Speed Uplink Packet Access (HSUPA) -based wireless networks (e.g., mobile networks), and complex Pi-sigma network (CPSN) -based wireless networks (e.g., Satellite network) and / or IEEE 802.11x based wireless communication network (e.g., wireless LAN network), and / or IEEE 802.16x based wireless communication network (e.g., mobile Internet), and / or Orthogonal Frequency Division Multiplexing Access (OFDMA) based 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) wireless communication network and the like.

Representative technologies that can provide IP mobility for TCP / IP-based application services when the wireless terminal performs handover between heterogeneous networks include CMIP (Client mobile IP) and PMIP (Proxy), which are standard technologies of the Internet Engineering Task Force (IETF). Mobile IP) and MOBIKE, and among these IP mobility providing technologies, PMIP is a technology that provides mobility by assigning one IP address to one wireless terminal.

The Windows operating system (Windows OS), which is widely used as an operating system of a wireless terminal, is implemented to allocate one IP address to one network interface. Therefore, when using the IPIP to provide IP mobility between the WiBro-HSDPA heterogeneous wireless network, the wireless terminal cannot simultaneously assign the same IP address to the WiBro modem and the HSDPA modem. Therefore, before performing the handover, the IP address assigned to the wireless modem used to access the currently connected wireless network must first be recovered, and then the same IP address must be assigned to the wireless modem to be used for connecting to the new wireless network (BBM (Break). -Before-Make) handover).

However, in case of BBM (Break-Before-Make) handover in the above manner, from the point of view of the wireless terminal, the communication is disconnected from the time of retrieving the IP address from the wireless modem currently in use to the time of assigning the IP address to the new wireless modem. This will occur.

Therefore, in the conventional art, when the PMIP is applied to the interworking between the portable Internet and the HSDPA heterogeneous wireless network to provide IP mobility, the same IP address may be different from each other due to the limitations of the wireless terminal using the Windows operating system. There is a problem that you cannot make Make-Before-Break (MBB) handover and make a Break-Before-Make (BBM) handover by not assigning to two wireless modems at the same time. Because of the over, communication disconnection occurs from the time of recovering the IP address assigned to the wireless modem currently in use to the assignment of the IP address to the wireless modem to be used in the new wireless network. Therefore, seamless handover between heterogeneous wireless networks is performed. There is a problem that is difficult to provide, and it is a problem of the present invention to solve this problem.

Accordingly, an object of the present invention is to provide a PMIP-based handover processing method for interworking heterogeneous networks to provide seamless handover when heterogeneous networks use PMIP (Proxy Mobile IP). .

That is, the present invention solves the problem of a Windows operating system (Windows OS) based wireless terminal, which has no choice but to perform a break-before-make (BBM) handover when a handover between heterogeneous networks using PMIP. It is an object of the present invention to provide a PMIP-based handover processing method for interworking heterogeneous networks to enable handover between heterogeneous networks without disconnection.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

The method of the present invention for achieving the above object, in the handover processing method, the wireless terminal is connected to the second wireless communication network while communicating with the first wireless communication network via the first wireless modem after the home IP to the second wireless modem An address assignment step of allocating an address HoA; A handover processing step of performing, by the wireless terminal, handover by changing a user traffic path from the first wireless modem to the second wireless modem; And terminating the wireless connection by which the wireless terminal is connected to the first wireless communication network.

On the other hand, another method of the present invention for achieving the above object, the handover processing method, the address recovery step of recovering a home IP address (HoA) is assigned to the second wireless modem by the wireless terminal; An address assignment step of the wireless terminal assigning a home IP address (HoA) to a first wireless modem and setting up an IP stack; A handover processing step of performing, by the wireless terminal, handover by changing a user traffic path from the second wireless modem to the first wireless modem; And a disconnection step of terminating the radio connection where the radio terminal is connected to the second radio communication network.

As described above, the present invention implements (implements) a virtual device driver (VDD) in a wireless terminal, and changes a user traffic path between the VDD, the HSDPA modem driver, and the WiBro modem driver. A terminal using a Windows OS may enable MBB (Make-Before-Break) handover, which was not possible when handover based on PMIP.

As described above, the present invention provides a BBM (Break-Before-Make) handover when providing IP mobility between a WiBro-HSDPA heterogeneous wireless network based on PMIP (Proxy Mobile IP). It is possible to provide handover between heterogeneous wireless networks without communication interruption by solving a problem of an OS) based wireless terminal to enable make-before-break (MBB) handover.

In addition, the present invention has the effect that it is possible to provide continuity of application services by allowing handover between heterogeneous wireless networks without disconnection of communication.

The above objects, features, and advantages will become more apparent from the detailed description given hereinafter with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention pertains may share the technical idea of the present invention. It will be easy to implement. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a general HSDPA network initial access signal procedure, and illustrates a signal procedure when the wireless terminal makes an initial connection to the HSDPA network.

First, the overall operation of the HSDPA network initial access signaling procedure, the HSDPA modem of the wireless terminal is a home IP address to the Gateway GPRS Support Node (GGSN) through a packet data protocol context activation procedure, one of the HSDPA access procedure (HoA) is requested, the GGSN receives a home IP address (HoA) from the Home Agent (Home Agent) through the PMIP registration procedure and delivers to the HSDPA modem of the wireless terminal. The HSDPA modem driver runs the Point-to-Point Protocol (PPP) to set up the IP stack.

Next, referring to FIG. 1, the general HSDPA network initial access signal procedure will be described in more detail as follows.

First, the HSDPA modem of the wireless terminal performs a wireless access and authentication procedure for accessing the HSDPA network (101). That is, the HSDPA modem of the wireless terminal performs a wireless connection and authentication procedure with the GGSN using an L2 connection establishment and authentication message (101).

Thereafter, the HSDPA modem of the wireless terminal performs a path establishment request procedure for the HSDPA network data service (102 to 104). That is, the HSDPA modem of the wireless terminal requests a packet data protocol context activation to a Serving GPRS Support Node (SGSN) using a packet data protocol context activation request message (102). Then, the SGSN requests the GGSN to create a packet data protocol context using a Create PDP Context Req message (103). Then, the GGSN requests the permission of the corresponding connection to the authentication server (AAA server) to be authenticated (104).

Thereafter, the GGSN performs a proxy mobile IP (PMIP) registration procedure (105, 106). That is, the GGSN requests registration from the home agent using a Proxy Registration ReQuest (PRRQ) message (105). Then, after the Home Agent allocates an IP address to the wireless terminal, the Home Agent transfers the corresponding IP address to the GGSN using a Proxy Registration Reply (PRRP) message (106). In this case, the PMIP client mounted on the GGSN actually performs the PMIP registration procedure with the home agent.

Thereafter, the GGSN transfers an IP address to be assigned to the wireless terminal to the SGSN using a packet data protocol context creation response (Create PDP Context Req) message (107). The SGSN then assigns an IP address to the wireless terminal using a Packet Data Protocol Context Accept message (108).

2 is a diagram illustrating a user traffic transmission path after initial access to an HSDPA network. FIG.

First, the application 201 forwards user traffic to a virtual device driver (VDD) 203 through an IP stack 202 to which an arbitrary IP address 'ABC' is assigned. The virtual device driver (VDD) 203 receives user traffic and replaces a source IP address of an IP header with a home IP address (HoA) from an arbitrary IP address 'ABC' and then an HSDPA modem. Send to driver 204.

On the other hand, for user traffic from the Internet to a wireless terminal (eg, a wireless terminal in an HSDPA network), the virtual device driver (VDD) 203 receives user traffic from the HSDPA modem driver 204 and receives a destination IP address. Is replaced with the IP address 'ABC' assigned to the IP stack 202 in the home IP address HoA, and then the user traffic is transferred to the application 201 through the IP stack 202. .

As described above, the virtual device driver (VDD) 203 is between the Arbitrary IP address 'ABC' assigned to the IP stack 202 for communication of the application and the home IP address (HoA). Perform mapping.

3 is a flowchart illustrating a handover method from an HSDPA network to a portable Internet (WiBro) network according to the present invention, wherein a wireless terminal transmits and receives user traffic through the HSDPA network and then handovers to the portable Internet (WiBro) network. The signal procedure to perform is shown.

From the standpoint of the wireless terminal, the WiBro connection procedure for handover is the same as the initial WiBro connection procedure (see FIG. 5) except for an IP allocation process. At this time, when handover from the HSDPA network to the WiBro network, the wireless terminal performs an IP allocation procedure through Dynamic Host Configuration Protocol (DHCP), unlike the initial WiBro connection procedure of FIG. 5 described later. I never do that.

On the other hand, when the WiBro connection procedure for handover is completed, the wireless terminal uses the home IP address (HoA), which is the IP address currently used in the HSDPA network, to use the DHCP procedure for the WiBro modem driver. To be forced (passive). After the IP address allocation is completed, the wireless terminal performs a handover by changing the user traffic path according to the handover procedure and terminates the existing HSDPA connection (see FIGS. 4A to 4C to be described later).

Next, the handover signal procedure from the HSDPA network to the WiBro network will be described in more detail with reference to FIG. 3.

First, when the handover from the HSDPA network to the WiBro network is started (301), the WiBro modem of the wireless terminal performs a wireless access and authentication procedure for accessing the WiBro network ( 302 to 309).

That is, the WiBro modem of the wireless terminal transmits an RNG Request (RNG-REQ) message to a RAS (Radio Access Station) of a WiBro network, and in response thereto, an RNG response (RNG-RSP). Using a procedure of receiving a message from a RAS of a WiBro network, timing of a radio signal according to a distance between a base station and a wireless terminal is adjusted and an available frequency channel is selected (302).

In addition, the WiBro modem of the wireless terminal transmits an SBC request (SBC-REQ) message to the RAS of the WiBro network, and in response, transmits an SBC response (SBC-RSP) message to the WiBro network. Using a procedure received from the RAS of the network, the provision function is negotiated between the base station and the wireless terminal (303).

The wireless terminal includes a PKM request (PKM-REQ) message and a PKM response (PKM-RSP) message between a WiBro modem and a RAS of a WiBro network, a RAS and a mobile Internet (WiBro) network. EPA request (EPA-REQ) message and EPA response (EPA-RSP) message with ACR of WiBro network, and access request / access request between ACR and authentication server (AAA server) of WiBro network. Using the Accept message, the authentication procedure is performed (304 to 306).

The wireless terminal includes a REG request (REG-REQ) message and a REG response (REG-RSP) message between the WiBro modem and the RAS of the WiBro network, and the RAS and the mobile Internet of the WiBro network. The negotiation procedure with the network for the Internet service is performed using a REG request (REG-REQ) message and an REG response (REG-RSP) message between ACRs of the (WiBro) network (307, 308).

The WiBro modem of the wireless terminal uses a DSA request (DSA-REQ) message, a DSA response (DSA-RSP) message, and a DSA acknowledgment (DSA-ACK) message with the RAS of the WiBro network. In operation 309, a service flow generation procedure for an Internet service is performed.

Thereafter, the access control router (ACR) of the WiBro network performs a proxy mobile IP (PMIP) registration procedure (310, 311). That is, the ACR of the WiBro network requests registration from the home agent using a Proxy Registration ReQuest (PRRQ) message (310). Then, after the Home Agent assigns an IP address to the wireless terminal, the home agent transfers the corresponding IP address to the ACR of the WiBro network using a PRRP (Proxy Registration RePly) message (311). At this time, in practice, the PMIP client mounted in the ACR of the WiBro network performs the PMIP registration procedure with the home agent.

Here, the wireless terminal does not perform an IP allocation procedure through the Dynamic Host Configuration Protocol (DHCP), unlike the WiBro initial access procedure of FIG. 5 described later.

Subsequently, when the HSDPA modem of the wireless terminal requests the HSDPA link release to the GGSN (312), the GGSN performs a PMIP registration cancellation procedure (313, 314). That is, the GGSN requests the termination of the registration to the home agent by setting the life time of the Proxy Registration ReQuest (PRRQ) message to '0' (313). Then, the home agent transmits a Proxy Registration Reply (PRRP) message to the GGSN (314), and terminates the tunnel between the home agent and the GGSN. At this time, the PMIP client mounted in the GGSN actually performs the PMIP registration cancellation procedure with the home agent.

4A to 4C are diagrams illustrating an embodiment of a method for processing PMIP-based handover according to the present invention, and a procedure for changing a transmission path of user traffic during handover from an HSDPA network to a WiBro network. It is shown.

4A to 4C illustrate a virtual device driver (VDD) 402, an HSDPA modem driver 401, and a WiBro modem driver (WiBro) of a wireless terminal during a handover from an HSDPA network to a WiBro network. 403 shows a procedure for changing the transmission path of user traffic. Here, the wireless terminal is a wireless terminal using a Windows operating system (Windows OS).

First, the wireless terminal performs the WiBro network connection procedure as described above in FIG. 3 while communicating with the HSDPA network through the HSDPA modem, and then forcibly (passively) the WiBro modem without using a DHCP procedure. Assigns a home IP address (HoA). At this time, the IP stack for the WiBro modem is not generated (see FIG. 4A).

When using the DHCP method used in the conventional WiBro connection procedure, an IP stack is generated on the WiBro modem side, and the IP stack of the generated WiBro modem side ( This is because when the home IP address (HoA) is assigned to the stack, communication is disconnected. That is, if the same home IP address (HoA) as the home IP address (HoA) already assigned to the IP stack of the HSDPA modem side is assigned to the IP stack of the WiBro modem side, the IP The stack will not work.

Thereafter, the virtual device driver (VDD) 402 of the wireless terminal changes the user traffic path from the current HSDPA modem to the WiBro modem to perform a handover (see FIG. 4B).

Thereafter, the wireless terminal terminates the wireless connection connected to the existing HSDPA network as described above in FIG. 3 (see FIG. 4C).

FIG. 5 is a flowchart illustrating an initial access signal procedure of a WiBro network, and illustrates a signal procedure when the wireless terminal makes an initial connection to a WiBro network.

The ACR of the WiBro network is assigned a home IP address (HoA), which is an IP address to be given to the wireless terminal from the home agent through the PMIP registration procedure, and the wireless terminal is assigned to the wireless Internet (WiBro) through the DHCP procedure. Configure the IP stack for the modem driver.

Next, referring to FIG. 5, the WiBro network initial access signal procedure will be described in more detail as follows.

First, a WiBro modem of a wireless terminal performs a wireless access and authentication procedure for accessing a WiBro network (501 to 508).

That is, the WiBro modem of the wireless terminal transmits an RNG Request (RNG-REQ) message to a RAS (Radio Access Station) of a WiBro network, and in response thereto, an RNG response (RNG-RSP). Using a procedure of receiving a message from a RAS of a WiBro network, a timing of a radio signal according to a distance between a base station and a wireless terminal is adjusted and an available frequency channel is selected (501).

In addition, the WiBro modem of the wireless terminal transmits an SBC request (SBC-REQ) message to the RAS of the WiBro network, and in response, transmits an SBC response (SBC-RSP) message to the WiBro network. Using the procedure received from the RAS of the network, the provision function between the base station and the wireless terminal is negotiated (502).

The wireless terminal includes a PKM request (PKM-REQ) message and a PKM response (PKM-RSP) message between a WiBro modem and a RAS of a WiBro network, a RAS and a mobile Internet (WiBro) network. EPA request (EPA-REQ) message and EPA response (EPA-RSP) message with ACR of WiBro network, and access request / access request between ACR and authentication server (AAA server) of WiBro network. Using the Accept) message, the authentication procedure is performed (503 to 505).

The wireless terminal includes a REG request (REG-REQ) message and a REG response (REG-RSP) message between the WiBro modem and the RAS of the WiBro network, and the RAS and the mobile Internet of the WiBro network. A negotiation procedure with a network for an Internet service is performed using a REG request (REG-REQ) message and an REG response (REG-RSP) message between ACRs of a (WiBro) network (506, 507).

The WiBro modem of the wireless terminal uses a DSA request (DSA-REQ) message, a DSA response (DSA-RSP) message, and a DSA acknowledgment (DSA-ACK) message with the RAS of the WiBro network. In operation 508, a service flow generation procedure for an Internet service is performed.

Subsequently, the WiBro modem of the wireless terminal performs an IP allocation procedure through Dynamic Host Configuration Protocol (DHCP) (509, 512 to 514).

That is, the WiBro modem of the wireless terminal transmits a DHCP Discover message to the ACR of the WiBro through RAS of the WiBro and requests IP allocation (509).

Upon receiving the DHCP Discover message, the ACR of the WiBro network receives a PMIP registration and receives a home IP address to be allocated to a terminal from a home agent (510, 511). That is, the ACR of the WiBro network requests registration from the home agent using a Proxy Registration ReQuest (PRRQ) message (510). Then, the home agent transfers the IP address to be allocated to the wireless terminal to the ACR of the WiBro network using a PRRP (Proxy Registration RePly) message (511). At this time, in practice, the PMIP client mounted in the ACR of the WiBro network performs the PMIP registration procedure with the home agent.

Subsequently, the ACR of the WiBro network transmits the IP address received from the home agent to the wireless terminal through a DHCP Offer message to inform the wireless terminal that the corresponding IP address is an available IP address (512). ).

Subsequently, the WiBro modem of the wireless terminal transmits a DHCP Request message to the ACR to inform that it intends to use the corresponding IP address (513).

Then, the ACR of the WiBro network transmits a DHCP ACK message to the wireless terminal to finally permit the use of the corresponding IP address (514).

FIG. 6 is a diagram illustrating a path for transmitting user traffic after initial connection to a WiBro network, and illustrates a path for transmitting user traffic after the wireless terminal completes initial connection to a WiBro network.

First, the application 601 forwards user traffic to a virtual device driver (VDD) 603 via an IP stack 602 to which an arbitrary IP address 'ABC' is assigned. The virtual device driver (VDD) 603 receives user traffic and replaces a source IP address of an IP header with a home IP address (HoA) from an arbitrary IP address 'ABC' and then executes the mobile Internet. (WiBro) Sends to the modem driver 604.

On the other hand, in the case of user traffic from the Internet to a wireless terminal (for example, a wireless terminal in a portable Internet network), the virtual device driver (VDD) 603 receives the user traffic from the WiBro modem driver 604 and receives a destination. (Destination) replaces the IP address with the IP address 'ABC' assigned to the IP stack 602 from the home IP address (HoA) and then to the application 601 through the IP stack 602 Pass user traffic.

As mentioned above, the virtual device driver (VDD) 603 is between the Arbitrary IP address 'ABC' and the home IP address (HoA) assigned to the IP stack 602 for communication of the application. Perform mapping.

7 is a flowchart illustrating a handover method from a portable Internet (WiBro) network to an HSDPA network according to an embodiment of the present invention, wherein a wireless terminal transmits and receives user traffic through a portable Internet (WiBro) network and hands the HSDPA network. The signal procedure to be over is shown.

From the point of view of the wireless terminal, the HSDPA access procedure for handover is the same as the initial HSDPA access procedure (see FIG. 1), and the GGSN equipped with the PMIP function performs the PMIP registration procedure with the home agent (HA). As a result, a home IP address (HoA), which is an IP address to be used by the wireless terminal, is given.

Next, the handover signal procedure from the WiBro network to the HSDPA network will be described in more detail with reference to FIG. 7.

First, when the handover from the WiBro network to the HSDPA network starts (701), the HSDPA modem of the wireless terminal performs a wireless access and authentication procedure for accessing the HSDPA network (702). That is, the HSDPA modem of the wireless terminal performs a wireless connection and authentication procedure with the GGSN by using an L2 connection establishment and authentication message (702).

Thereafter, the HSDPA modem of the wireless terminal performs a path establishment request procedure for the HSDPA network data service (703 to 705). That is, the HSDPA modem of the wireless terminal requests a packet data protocol context activation to a Serving GPRS Support Node (SGSN) using a packet data protocol context activation request message (703). Then, the SGSN requests the packet data protocol context creation to the GGSN using the Create PDP Context Req message (704). Then, the GGSN requests the permission of the corresponding connection to the authentication server (AAA server) to be authenticated (705).

Thereafter, the GGSN performs a proxy mobile IP (PMIP) registration procedure (706, 707). That is, the GGSN requests registration to the home agent using a Proxy Registration ReQuest (PRRQ) message (706). Then, after the Home Agent allocates an IP address to the wireless terminal, the Home Agent transfers the corresponding IP address to the GGSN using a Proxy Registration Reply (PRRP) message (707). In this case, the PMIP client mounted on the GGSN actually performs the PMIP registration procedure with the home agent.

Thereafter, the GGSN transfers an IP address to be assigned to the wireless terminal to the SGSN using a packet data protocol context creation response (Create PDP Context Req) message (708). The SGSN then assigns an IP address to the wireless terminal using an Packet Data Protocol Context Accept message (709).

Subsequently, when the WiBro modem of the wireless terminal releases the WiBro link (710), the RAS notifies the WiBro Link Release to the ACR (711).

Then, the ACR performs a Proxy Mobile IP (PMIP) deregistration procedure (712, 713). That is, the ACR requests the termination of registration to the home agent by setting the life time of the Proxy Registration ReQuest (PRRQ) message to '0' (712). Then, the home agent transmits a PRRP (Proxy Registration RePly) message to the ACR (713), and terminates the tunnel between the home agent and the ACR. At this time, in practice, the PMIP client mounted in the ACR performs the procedure of canceling the PMIP registration with the home agent.

8A to 8C are diagrams illustrating another embodiment of a method for processing PMIP-based handover according to the present invention, and a procedure for changing a transmission path of user traffic when handover from a WiBro network to an HSDPA network is performed. It is shown.

That is, FIGS. 8A to 8C illustrate a virtual device driver (VDD) 802, an HSDPA modem driver 801, and a WiBro modem driver (WiBro) of a wireless terminal during handover from a WiBro network to an HSDPA network. 803 shows a procedure for changing the transmission path of user traffic. Here, the wireless terminal is a wireless terminal using a Windows operating system (Windows OS).

First, the wireless terminal releases the IP stack allocated to the WiBro modem through a DHCP release. That is, the wireless terminal retrieves the home IP address HoA assigned to the WiBro modem through the DHCP release (see FIG. 8A). In this case, when the DHCP release is performed, only the IP stack of the wireless terminal is terminated, but the virtual device driver (VDD) 802 transfers IP packets with the WiBro network side through a WiBro modem. You can continue to send and receive.

After recovering the home IP address (HoA) assigned to the WiBro modem through the DHCP release as described above, the wireless terminal continues to transmit and receive user traffic through the WiBro network. Attempt to connect to the HSDPA network as described above. At this time, the wireless terminal allocates a home IP address (HoA) to the HSDPA modem through PPP in the process of accessing the HSDPA network and sets up an IP stack for the HSDPA modem (see FIG. 8B). Then, the wireless terminal is ready to communicate through the HSDPA network.

Thereafter, the virtual device driver (VDD) 802 of the wireless terminal changes the user traffic path from the current WiBro modem to the HSDPA modem to perform a handover (see FIG. 8C).

Thereafter, the wireless terminal terminates the wireless connection connected to the existing (previous) WiBro network as described above with reference to FIG. 7.

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention is based on Code Division Multiple Access (CDMA) operating in a synchronous manner, Wide-CDMA (WCDMA) and / or High Speed Downlink Packet Access (HSDPA) and / or High Speed Uplink Packet Access (HSUPA) operation in an asynchronous manner. Wireless communication networks (e.g. mobile networks), complex pi-sigma network (CPSN) -based wireless networks (e.g. satellite networks), and / or IEEE 802.11x-based wireless networks (e.g. wireless LAN networks), and / or IEEE 802.16x It can be used in a wireless communication network (for example, the portable Internet), and / or an Orthogonal Frequency Division Multiplexing Access (OFDMA) based 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) wireless communication network.

1 is a flowchart illustrating a general HSDPA network initial access signal procedure;

2 is a diagram illustrating a user traffic transmission path after initial access to an HSDPA network;

3 is a flowchart illustrating a handover method from an HSDPA network to a WiBro network according to the present invention;

4a to 4c are diagrams illustrating an embodiment of a method for processing PMIP-based handover according to the present invention;

FIG. 5 is a flowchart illustrating an initial access signal procedure of a WiBro network; FIG.

6 is a diagram illustrating a user traffic transmission path after initial access to a WiBro network;

7 is a flowchart illustrating a handover method from a WiBro network to an HSDPA network according to the present invention;

8A to 8C are diagrams illustrating another embodiment of a method for processing PMIP-based handover according to the present invention.

* Explanation of symbols for the main parts of the drawings

401, 801: HSDPA Modem Driver

402, 802: Virtual Device Driver (VDD)

403 and 803: WiBro Modem Driver

Claims (13)

In the handover processing method, An address assignment step of assigning a home IP address (HoA) to the second wireless modem after the wireless terminal connects to the second wireless communication network while communicating with the first wireless communication network through the first wireless modem; A handover processing step of performing, by the wireless terminal, handover by changing a user traffic path from the first wireless modem to the second wireless modem; And Terminating the wireless connection by the wireless terminal to the first wireless communication network Handover processing method comprising a. The method of claim 1, The address assignment step, Handover processing method for forcibly assigning a home IP address (HoA) to the second wireless modem. The method of claim 1, The handover processing step, A virtual device driver (VDD) is mounted in the wireless terminal, And the virtual device driver (VDD) changes a user traffic path from the first wireless modem to the second wireless modem to perform a handover. In the handover processing method, An address retrieval step of retrieving a home IP address HoA assigned to the second wireless modem by the wireless terminal; An address assignment step of the wireless terminal assigning a home IP address (HoA) to a first wireless modem and setting up an IP stack; A handover processing step of performing, by the wireless terminal, handover by changing a user traffic path from the second wireless modem to the first wireless modem; And Disconnection step of canceling a wireless connection where the wireless terminal is connected to a second wireless communication network Handover processing method comprising a. The method of claim 4, wherein The address retrieval step, The wireless terminal releases the IP stack allocated to the second wireless modem through a DHCP release to recover the home IP address HoA assigned to the second wireless modem. . The method of claim 5, The address retrieval step, Even if the wireless terminal releases the IP stack allocated to the second wireless modem through a DHCP release and recovers a home IP address HoA assigned to the second wireless modem, the wireless terminal And a virtual device driver (VDD) mounted in the network continuously transmits and receives an IP packet to and from the second wireless communication network through the second wireless modem. The method of claim 4, wherein The address assignment step, And a wireless terminal assigns a home IP address (HoA) to the first wireless modem and establishes an IP stack for the first wireless modem during a connection to the first wireless communication network. The method of claim 4, wherein The handover processing step, A virtual device driver (VDD) is mounted in the wireless terminal, And the virtual device driver (VDD) changes a user traffic path from the second wireless modem to the first wireless modem to perform a handover. The method according to any one of claims 4 to 8, The disconnection step, The handover processing method of removing a DHCP release on the second wireless modem side. The method according to claim 3 or 8, And the virtual device driver (VDD) performs a mapping between an arbitrary IP address and a home IP address HoA assigned to the wireless terminal. 9. The method according to any one of claims 1 to 8, The home IP address HoA of the address assignment step is Handover processing method characterized in that the IP address assigned on the basis of PMIP from the external home agent (HA). 9. The method according to any one of claims 1 to 8, The wireless terminal, A handover processing method comprising a wireless terminal using a Windows operating system (Windows OS). 13. The method of claim 12, Wherein the first wireless communication network is a High Speed Downlink Packet Access (HSDPA) network, and the second wireless communication network is a WiBro network.

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